[R] problem with apply(m, 1, min, na.rm=T)

[Rolf Turner]

On 21/01/2009, at 12:26 PM, Czerminski, Ryszard wrote:

> Passing extra arguments to FUN=mean or median in apply
> seems fine, but when FUN=min warnings are generated?
> See below.
>
> Any ideas why?
>
> Best regards,
> Ryszard
>
> Ryszard Czerminski
> AstraZeneca Pharmaceuticals LP
>
>> m
>      [,1] [,2]
> [1,]    1    2
> [2,]    3   NA
> [3,]   NA   NA
>> apply(m, 1, median, na.rm=T)
> [1] 1.5 3.0  NA
>> apply(m, 1, mean, na.rm=T)
> [1] 1.5 3.0 NaN
>> apply(m, 1, min, na.rm=T)
> [1]   1   3 Inf
> Warning message:
> In FUN(newX[, i], ...) : no non-missing arguments to min; returning  
> Inf

RTFM:

      The minimum and maximum of a numeric empty set are '+Inf' and
      '-Inf' (in this order!) which ensures _transitivity_, e.g.,
      'min(x1, min(x2)) == min(x1, x2)'.  For numeric 'x' 'max(x) ==
      -Inf' and 'min(x) == +Inf' whenever 'length(x) == 0' (after
      removing missing values if requested).

	cheers,

		Rolf Turner

######################################################################
Attention:\ This e-mail message is privileged and confid...{{dropped:9}}